中文摘要：

根据单元机组低阶非线性模型,经过适当简化,推导出能够描述机组动态特性及机炉耦合关系的通用线性模型。以该模型为基础,采用有限带宽控制的分散相对增益法（dRG）从理论上进行了分散控制结构分析,并对得出的分散控制结构利用独立设计法整定PID控制器参数,保证系统稳定性。当系统耦合严重、完全分散控制不能满足系统性能要求时,采用格拉姆（Gramian）法进行部分分散控制结构分析,并在分散及集中控制器基础上整定出部分分散控制器参数。仿真对比试验表明部分分散控制系统能达到与多变量协调控制系统相近的性能,而且部分分散控制结构更简单、设计及调试方法更容易。

英文摘要：

Based on a low-order nonlinear model of a boiler-turbine unit,a simplified general model which can capture the essential dynamics and interaction of a unit is derived in this paper.The control structure of this model is analyzed via the decentralized relative gain method（dRG） under the condition of finite-bandwidth control.Then independent design principle is applied to design the decentralized PID controllers and the stability of closed loop can be guaranteed.When the coupling is strong and the fully decentralized structure can not meet the desired performance,Gramian method is applied to analyze the partially decentralized structure of the model,and based on the decentralized and the centralized controller,the resulting controller is tuned.Simulation results show that partially decentralized controller can achieve comparable performance as the centralized one;furthermore it has a simpler structure and is easier to implement and tune.